IDS-C and IDS-SR: Psychometric properties in depressed in-patients

Abstract

Sixty-eight depressed in-patients were assessed at admission (DO), and after 5 days (D5), ten days (D10) and 28 days (D28) of antidepressant treatment, with the Inventory for Depressive Symptomatology-Clinician (IDS-C) and the Inventory for Depressive Symptomatology-Self-Rated (IDS-SR) (Rush et al., 1986), the Montgomery and Asberg Depression Rating Scale (MADRS) (Montgomery and Asberg, 1979) and the depression factor of the Symptom Check List (SCL-90R) (Derogatis, 1977), in order to assess IDS-C and IDS-SR psychometric properties in depressed in-patients and to compare IDS-C to MADRS and IDS-SR to the SCL-90R depression factor. Most of the IDS-C and IDS-SR items were significantly correlated to the final score and the Cronbach alpha coefficients were high (0.75 for the IDS-C and 0.79 for the IDS-SR). Principal Component Analyses (PCA) showed three factors for both IDS-C and IDS-SR: 'depression', 'anxiety/arousal' and 'sleep/appetite'. These results suggest satisfactory internal consistency of IDS-C and IDS-SR. Concurrent validity of the IDS-C with the MADRS was high (r = 0.81), as well as concurrent validity of the IDS-SR with the SCL-90R depression factor (r = 0.84). Concerning sensitivity to change, the four scales were able to discriminate between different levels of severity of depression. Moreover, considering paired t-tests on score changes, IDS-C sensitivity to change may be higher than MADRS sensitivity to change, this phenomenon being related to the number of items…